Traffic cones are placed on roads and highways at regular intervals to deflect the traffic from a lane that is to be taken out of operation. These are generally plastic cones, having a hollow conical body, provided at its end opposite the summit with a flat base having a generally square outline. To place them, the cones are transported by a driven or trailer vehicle in the form of stacks by interfitting within each other. Their distribution is effected by personnel riding the vehicles and requires two operations, one taking a cone from the stack and giving it to the operator who places it on the street. Such an operation is not without danger. Moreover, it is difficult in this case to ensure a distribution of the cones at regular intervals. It has therefore been sought in certain cases to render automatic or semiautomatic certain phases of each of these operations.
German patent DE-A-2.747.183 discloses a device for the automatic placement of cones in which the cones, stored in stacks, are successively moved into vertical position above an opening through which each cone is capable of falling by simple gravity, a plate and a movable fork acting alternatively in synchronous manner, the one freeing the lowermost cone while the other holds back the cone immediately above in said pile, the opposite movement of each of these forks permitting the second cone to take its place on said plate for the next emplacement while the upper fork itself is in place to retain the upper cones. Such a cone system requires perfect synchronism between the various movable elements to ensure distribution of the cones. However, it is known that because of the properties of the cones, namely their ability to deform at high temperatures and their heterogeneity arising from variations in shape during manufacture, only a static distribution system not requiring adjustment, offers maximum dependability. Moreover, such a device cannot be used again to collect the cones.
Another device described in French patent FR-A-2.657.313 is comprised by a wheel placed on the side of the truck. This wheel is constituted by two rotatable truncated conical circular panels which delimit between them a space capable of receiving the cones and gripping them for moving them. The problem with this device resides in the fact that the supply and the collection of the cones require the presence of an operator who must supply or collect one by one the cones disposed along the street.
A completely automatic system has on the other hand been described in French patent FR-A-2.556.378. This device is complex and cumbersome because of the presence of numerous chutes and conveyor belts. It is to be noted that, in this device, the placement of the cones has the same drawbacks as those cited in the case of German patent No. 2.747.183. Thus, each supply comprises at its lower end two superposed abutments which engage respectively below the last or next-to-last cone, which abutments are actuated by articulated levers which are interconnected by a strap such that the lower abutment is withdrawn and lets fall one cone, while the upper abutment is engaged below the next-to-last cone, and vice versa.
All of these devices requiring delicate synchronism and the displacement of members have shown their limit of reliability with time.